The island region, which comprises the islands of Bioco and Annobón (2,017 and 17 km2 in area respectively), borders in the north with Nigeria and in the east with the Republic of Cameroon, which lies around 30 kilometres away; Bioco is around 250 kilometres to the north of Río Muni.
La región insular, que comprende las islas de Bioko y Annobón (2.017 y 17 km2 respectivamente), limita al norte con Nigeria y al este con la República del Camerún, de la que dista unos 30 km; Bioko está situada a unos 250 km al norte de Río Muni.